Mario Draghi, president of the ECB, will provide the reason behind the decision by the ECB's Governing Council at a news conference later today in Slovenia. The council meets twice a year away from its Frankfurt headquarters.
The ECB cut its key refinancing rate in July to 0.75 percent and the rate it pays on overnight balances to zero in an effort to entice banks to keep money in the economy.
Most economists had expected the ECB to keep rates on hold today following last month's long-awaited announcement of its bond-buying program as inflation remains above the bank's target of inflation that is close to, but below 2 percent. Inflation rose to 2.7 percent in September from August.
Economic growth, however, remains very weak, with Gross Domestic Product shrinking by 0.2 percent in the second quarter from the first following zero growth in the first quarter.
On an annual basis, the economy was 0.5 percent smaller in the second quarter of this year compared with the same quarter in 2011.